android ContentProvider
ContentProvider 实现了数据间的共享，一个应用可以有多个ContentProvider ，一个ContentProvider可以有多个表结构，实例如下"
1.多个ContentProvider
import android.content.ContentProvider;
import android.content.ContentResolver;
import android.content.ContentUris;
import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import android.database.sqlite.SQLiteQueryBuilder;
import android.net.Uri;
import android.provider.Settings;
import android.text.TextUtils;
import android.util.Log;
public class DownLoadBookmarkProvider extends ContentProvider{
private static final String TAG = "DownLoadBookmarkProvider";
private static final boolean LOGD =false;
private static final String DATABASE_NAME = "download.db";
private static final int DATABASE_VERSION = 1;
public static final Uri uri=Uri.parse("content://com.android.user/bookmark");//com.android.user 是用于访问db的权限uri，在配置文件中要定义，同时访问的uri中要在content后面附加，用于指定这个访问路径权限
static final String AUTHORITY = "com.android.user";
static final String TABLE_BOOKMARK = "user";
static final String PARAMETER_NOTIFY = "notify";
private SQLiteOpenHelper mOpenHelper;
@Override
public boolean onCreate() {
if(LOGD)Log.i(TAG, "=onCreate===");
mOpenHelper = new DatabaseHelper(getContext());
return (mOpenHelper == null) ? false : true;
}
@Override
public String getType(Uri uri) {
SqlArguments args = new SqlArguments(uri, null, null);
if (TextUtils.isEmpty(args.where)) {
return "vnd.android.cursor.dir/" + args.table;
} else {
return "vnd.android.cursor.item/" + args.table;
}
}
///content://com.android.launcherdemo.settings/favorites?notify=true;
@Override
public Cursor query(Uri uri, String[] projection, String selection,
String[] selectionArgs, String sortOrder) {
SqlArguments args = new SqlArguments(uri, selection, selectionArgs);
SQLiteQueryBuilder qb = new SQLiteQueryBuilder();
qb.setTables(args.table);//url.getPathSegments().get(0)
SQLiteDatabase db = mOpenHelper.getWritableDatabase();
Cursor result = qb.query(db, projection, args.where, args.args, null, null, sortOrder);
result.setNotificationUri(getContext().getContentResolver(), uri);
return result;
}
@Override
public Uri insert(Uri uri, ContentValues initialValues) {
SqlArguments args = new SqlArguments(uri);
SQLiteDatabase db = mOpenHelper.getWritableDatabase();
final long rowId = db.insert(args.table, null, initialValues);
if (rowId <= 0) return null;
uri = ContentUris.withAppendedId(uri, rowId);
sendNotify(uri);
return uri;
}
@Override
public int bulkInsert(Uri uri, ContentValues[] values) {
SqlArguments args = new SqlArguments(uri);
SQLiteDatabase db = mOpenHelper.getWritableDatabase();
db.beginTransaction();
try {
int numValues = values.length;
for (int i = 0; i < numValues; i++) {
if (db.insert(args.table, null, values[i]) < 0) return 0;
}
db.setTransactionSuccessful();
} finally {
db.endTransaction();
}
sendNotify(uri);
return values.length;
}
@Override
public int delete(Uri uri, String selection, String[] selectionArgs) {
SqlArguments args = new SqlArguments(uri, selection, selectionArgs);
SQLiteDatabase db = mOpenHelper.getWritableDatabase();
int count = db.delete(args.table, args.where, args.args);
if (count > 0) sendNotify(uri);
return count;
}
@Override
public int update(Uri uri, ContentValues values, String selection, String[] selectionArgs) {
SqlArguments args = new SqlArguments(uri, selection, selectionArgs);
SQLiteDatabase db = mOpenHelper.getWritableDatabase();
int count = db.update(args.table, values, args.where, args.args);
if (count > 0) sendNotify(uri);
return count;
}
private void sendNotify(Uri uri) {
String notify = uri.getQueryParameter(PARAMETER_NOTIFY);
if (notify == null || "true".equals(notify)) {
getContext().getContentResolver().notifyChange(uri, null);
}
}
private static class DatabaseHelper extends SQLiteOpenHelper {
private final Context mContext;
DatabaseHelper(Context context) {
super(context, DATABASE_NAME, null, DATABASE_VERSION);
mContext = context;
}
@Override
public void onCreate(SQLiteDatabase db) {
if (LOGD) Log.d(TAG, "creating new launcher database");
db.execSQL("CREATE TABLE bookmark (" +
"_id INTEGER PRIMARY KEY," +
"title TEXT" +
");");
// Database was just created, so wipe any previous widgets
if (!convertDatabase(db)) {
}
}
private boolean convertDatabase(SQLiteDatabase db) {
if (LOGD) Log.d(TAG, "converting database from an older format, but not onUpgrade");
boolean converted = false;
final Uri uri = Uri.parse("content://" + Settings.AUTHORITY +
"/old_favorites?notify=true");
final ContentResolver resolver = mContext.getContentResolver();
Cursor cursor = null;
try {
cursor = resolver.query(uri, null, null, null, null);
} catch (Exception e) {
// Ignore
}
// We already have a favorites database in the old provider
if (cursor != null && cursor.getCount() > 0) {
try {
converted = copyFromCursor(db, cursor) > 0;
} finally {
cursor.close();
}
if (converted) {
resolver.delete(uri, null, null);
}
}
return converted;
}
private int copyFromCursor(SQLiteDatabase db, Cursor c) {
/* final int idIndex = c.getColumnIndexOrThrow(LauncherSettings.Favorites._ID);
ContentValues[] rows = new ContentValues[c.getCount()];
int i = 0;
while (c.moveToNext()) {
ContentValues values = new ContentValues(c.getColumnCount());
values.put(LauncherSettings.Favorites._ID, c.getLong(idIndex));
rows[i++] = values;
}
db.beginTransaction();
int total = 0;
try {
int numValues = rows.length;
for (i = 0; i < numValues; i++) {
if (db.insert(TABLE_FAVORITES, null, rows[i]) < 0) {
return 0;
} else {
total++;
}
}
db.setTransactionSuccessful();
} finally {
db.endTransaction();
}
return total;*/
return 0;
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
if (LOGD) Log.d(TAG, "onUpgrade triggered");
int version = oldVersion;
if (version != DATABASE_VERSION) {
Log.w(TAG, "Destroying all old data.");
db.execSQL("DROP TABLE IF EXISTS " + TABLE_BOOKMARK);
onCreate(db);
}
}
}
static class SqlArguments {
public final String table;
public final String where;
public final String[] args;
SqlArguments(Uri url, String where, String[] args) {
if (url.getPathSegments().size() == 1) {
this.table = url.getPathSegments().get(0);
this.where = where;
this.args = args;
} else if (url.getPathSegments().size() != 2) {
throw new IllegalArgumentException("Invalid URI: " + url);
} else if (!TextUtils.isEmpty(where)) {
throw new UnsupportedOperationException("WHERE clause not supported: " + url);
} else {
this.table = url.getPathSegments().get(0);///content://com.android.launcherdemo.settings/favorites?notify=true;
this.where = "_id=" + ContentUris.parseId(url);
this.args = null;
}
}
SqlArguments(Uri url) {
if (url.getPathSegments().size() == 1) {
table = url.getPathSegments().get(0);
where = null;
args = null;
} else {
throw new IllegalArgumentException("Invalid URI: " + url);
}
}
}
}
第二个Contentprovider
import android.content.ContentProvider;
import android.content.ContentResolver;
import android.content.ContentUris;
import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import android.database.sqlite.SQLiteQueryBuilder;
import android.net.Uri;
import android.provider.Settings;
import android.text.TextUtils;
import android.util.Log;
public class PlauginProvider extends ContentProvider{
private static final String TAG = "PlauginProvider";
private static final boolean LOGD =true;
private static final String DATABASE_NAME = "email.db";
private static final int DATABASE_VERSION = 1;
public static final Uri uri=Uri.parse("content://com.android.email/email");//最后的email是访问的表 com.android.email是访问的路径权限，在配置文件中要定义
static final String AUTHORITY = "com.android.email";
static final String TABLE_PLAUGIN= "emails";
static final String PARAMETER_NOTIFY = "notify";
private SQLiteOpenHelper mOpenHelper;
@Override
public boolean onCreate() {
if(LOGD)Log.i(TAG, "=onCreate===");
mOpenHelper = new DatabaseHelper(getContext());
return (mOpenHelper == null) ? false : true;
}
@Override
public String getType(Uri uri) {
SqlArguments args = new SqlArguments(uri, null, null);
if (TextUtils.isEmpty(args.where)) {
return "vnd.android.cursor.dir/" + args.table;
} else {
return "vnd.android.cursor.item/" + args.table;
}
}
///content://com.android.launcherdemo.settings/favorites?notify=true;
@Override
public Cursor query(Uri uri, String[] projection, String selection,
String[] selectionArgs, String sortOrder) {
SqlArguments args = new SqlArguments(uri, selection, selectionArgs);
SQLiteQueryBuilder qb = new SQLiteQueryBuilder();
qb.setTables(args.table);//url.getPathSegments().get(0)
SQLiteDatabase db = mOpenHelper.getWritableDatabase();
Cursor result = qb.query(db, projection, args.where, args.args, null, null, sortOrder);
result.setNotificationUri(getContext().getContentResolver(), uri);
return result;
}
@Override
public Uri insert(Uri uri, ContentValues initialValues) {
SqlArguments args = new SqlArguments(uri);
SQLiteDatabase db = mOpenHelper.getWritableDatabase();
final long rowId = db.insert(args.table, null, initialValues);
if (rowId <= 0) return null;
uri = ContentUris.withAppendedId(uri, rowId);
sendNotify(uri);
return uri;
}
@Override
public int bulkInsert(Uri uri, ContentValues[] values) {
SqlArguments args = new SqlArguments(uri);
SQLiteDatabase db = mOpenHelper.getWritableDatabase();
db.beginTransaction();
try {
int numValues = values.length;
for (int i = 0; i < numValues; i++) {
if (db.insert(args.table, null, values[i]) < 0) return 0;
}
db.setTransactionSuccessful();
} finally {
db.endTransaction();
}
sendNotify(uri);
return values.length;
}
@Override
public int delete(Uri uri, String selection, String[] selectionArgs) {
SqlArguments args = new SqlArguments(uri, selection, selectionArgs);
SQLiteDatabase db = mOpenHelper.getWritableDatabase();
int count = db.delete(args.table, args.where, args.args);
if (count > 0) sendNotify(uri);
return count;
}
@Override
public int update(Uri uri, ContentValues values, String selection, String[] selectionArgs) {
SqlArguments args = new SqlArguments(uri, selection, selectionArgs);
SQLiteDatabase db = mOpenHelper.getWritableDatabase();
int count = db.update(args.table, values, args.where, args.args);
if (count > 0) sendNotify(uri);
return count;
}
private void sendNotify(Uri uri) {
String notify = uri.getQueryParameter(PARAMETER_NOTIFY);
if (notify == null || "true".equals(notify)) {
getContext().getContentResolver().notifyChange(uri, null);
}
}
private static class DatabaseHelper extends SQLiteOpenHelper {
private final Context mContext;
DatabaseHelper(Context context) {
super(context, DATABASE_NAME, null, DATABASE_VERSION);
mContext = context;
}
@Override
public void onCreate(SQLiteDatabase db) {
if (LOGD) Log.d(TAG, "creating new plaugin database");
db.execSQL("CREATE TABLE plaugin (" +
"_id INTEGER," +
"title TEXT" +
");");
// Database was just created, so wipe any previous widgets
if (!convertDatabase(db)) {
}
}
private boolean convertDatabase(SQLiteDatabase db) {
if (LOGD) Log.d(TAG, "converting database from an older format, but not onUpgrade");
boolean converted = false;
final Uri uri = Uri.parse("content://" + Settings.AUTHORITY +
"/old_favorites?notify=true");
final ContentResolver resolver = mContext.getContentResolver();
Cursor cursor = null;
try {
cursor = resolver.query(uri, null, null, null, null);
} catch (Exception e) {
// Ignore
}
// We already have a favorites database in the old provider
if (cursor != null && cursor.getCount() > 0) {
try {
converted = copyFromCursor(db, cursor) > 0;
} finally {
cursor.close();
}
if (converted) {
resolver.delete(uri, null, null);
}
}
return converted;
}
private int copyFromCursor(SQLiteDatabase db, Cursor c) {
/* final int idIndex = c.getColumnIndexOrThrow(LauncherSettings.Favorites._ID);
ContentValues[] rows = new ContentValues[c.getCount()];
int i = 0;
while (c.moveToNext()) {
ContentValues values = new ContentValues(c.getColumnCount());
values.put(LauncherSettings.Favorites._ID, c.getLong(idIndex));
rows[i++] = values;
}
db.beginTransaction();
int total = 0;
try {
int numValues = rows.length;
for (i = 0; i < numValues; i++) {
if (db.insert(TABLE_FAVORITES, null, rows[i]) < 0) {
return 0;
} else {
total++;
}
}
db.setTransactionSuccessful();
} finally {
db.endTransaction();
}
return total;*/
return 0;
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
if (LOGD) Log.d(TAG, "onUpgrade triggered");
int version = oldVersion;
if (version != DATABASE_VERSION) {
Log.w(TAG, "Destroying all old data.");
db.execSQL("DROP TABLE IF EXISTS " + TABLE_PLAUGIN);
onCreate(db);
}
}
}
static class SqlArguments {
public final String table;
public final String where;
public final String[] args;
SqlArguments(Uri url, String where, String[] args) {
if (url.getPathSegments().size() == 1) {
this.table = url.getPathSegments().get(0);
this.where = where;
this.args = args;
} else if (url.getPathSegments().size() != 2) {
throw new IllegalArgumentException("Invalid URI: " + url);
} else if (!TextUtils.isEmpty(where)) {
throw new UnsupportedOperationException("WHERE clause not supported: " + url);
} else {
this.table = url.getPathSegments().get(0);///content://com.android.launcherdemo.settings/favorites?notify=true;
this.where = "_id=" + ContentUris.parseId(url);
this.args = null;
}
}
SqlArguments(Uri url) {
if (url.getPathSegments().size() == 1) {
table = url.getPathSegments().get(0);
where = null;
args = null;
} else {
throw new IllegalArgumentException("Invalid URI: " + url);
}
}
}
}
配置文件：
<provider android:name=".DownLoadBookmarkProvider" android:authorities="com.aqndroid.user"/> //访问文件的路径的权限
<provider android:name=".PlauginProvider" android:authorities="com.android.email"/>
2.一个ContentProvider创建多个表结构
package com.android.test.broadcast;
import android.content.ContentProvider;
import android.content.ContentResolver;
import android.content.ContentUris;
import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.SQLException;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import android.database.sqlite.SQLiteQueryBuilder;
import android.net.Uri;
import android.provider.Settings;
import android.text.TextUtils;
import android.util.Log;
public class MyContentProvider extends ContentProvider{
private static final boolean LOGD =false;
private SQLiteDatabase mySqlDB;
private DatabaseHelper mDBHelpler;
private static final String DATABASE_NAME = "Users.db";
private static final int DATABASE_VERSION = 1;
private static final String TABLE_NAME = "contcats";
private static final String TABLE_USER = "user";
private static final String TAG ="MyContentProvider";
public static final String author="hello";
public static final Uri ContentUserUri=Uri.parse("content://hello/user");//user表访问的路径，hello控制路径访问权限，在配置文件中要定义
public static final Uri ContentContactUri=Uri.parse("content://hello/contcats");//contacts表访问的路径
static final String PARAMETER_NOTIFY = "notify";
private SQLiteOpenHelper mOpenHelper;
private static class DatabaseHelper extends SQLiteOpenHelper {
private final Context mContext;
DatabaseHelper(Context context) {
super(context, DATABASE_NAME, null, DATABASE_VERSION);
mContext = context;
}
@Override
public void onCreate(SQLiteDatabase db) {
if (LOGD) Log.d(TAG, "creating new launcher database");
db.execSQL("Create table " + TABLE_NAME + "( _id INTEGER PRIMARY KEY AUTOINCREMENT, CONTACTS_NAME TEXT);");
db.execSQL("Create table " + TABLE_USER + "( _id INTEGER PRIMARY KEY AUTOINCREMENT, age INTEGER);");
// Database was just created, so wipe any previous widgets
if (!convertDatabase(db)) {
}
}
private boolean convertDatabase(SQLiteDatabase db) {
if (LOGD) Log.d(TAG, "converting database from an older format, but not onUpgrade");
boolean converted = false;
final Uri uri = Uri.parse("content://" + Settings.AUTHORITY +
"/old_favorites?notify=true");
final ContentResolver resolver = mContext.getContentResolver();
Cursor cursor = null;
try {
cursor = resolver.query(uri, null, null, null, null);
} catch (Exception e) {
// Ignore
}
// We already have a favorites database in the old provider
if (cursor != null && cursor.getCount() > 0) {
try {
converted = copyFromCursor(db, cursor) > 0;
} finally {
cursor.close();
}
if (converted) {
resolver.delete(uri, null, null);
}
}
return converted;
}
private int copyFromCursor(SQLiteDatabase db, Cursor c) {
/* final int idIndex = c.getColumnIndexOrThrow(LauncherSettings.Favorites._ID);
ContentValues[] rows = new ContentValues[c.getCount()];
int i = 0;
while (c.moveToNext()) {
ContentValues values = new ContentValues(c.getColumnCount());
values.put(LauncherSettings.Favorites._ID, c.getLong(idIndex));
rows[i++] = values;
}
db.beginTransaction();
int total = 0;
try {
int numValues = rows.length;
for (i = 0; i < numValues; i++) {
if (db.insert(TABLE_FAVORITES, null, rows[i]) < 0) {
return 0;
} else {
total++;
}
}
db.setTransactionSuccessful();
} finally {
db.endTransaction();
}
return total;*/
return 0;
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
if (LOGD) Log.d(TAG, "onUpgrade triggered");
int version = oldVersion;
if (version != DATABASE_VERSION) {
Log.w(TAG, "Destroying all old data.");
db.execSQL("DROP TABLE IF EXISTS user");
db.execSQL("DROP TABLE IF EXISTS contacts");
onCreate(db);
}
}
}
@Override
public boolean onCreate() {
if(LOGD)Log.i(TAG, "=onCreate===");
mOpenHelper = new DatabaseHelper(getContext());
return (mOpenHelper == null) ? false : true;
}
@Override
public String getType(Uri uri) {
SqlArguments args = new SqlArguments(uri, null, null);
if (TextUtils.isEmpty(args.where)) {
return "vnd.android.cursor.dir/" + args.table;
} else {
return "vnd.android.cursor.item/" + args.table;
}
}
///content://com.android.launcherdemo.settings/favorites?notify=true;
@Override
public Cursor query(Uri uri, String[] projection, String selection,
String[] selectionArgs, String sortOrder) {
SqlArguments args = new SqlArguments(uri, selection, selectionArgs);
SQLiteQueryBuilder qb = new SQLiteQueryBuilder();
qb.setTables(args.table);//url.getPathSegments().get(0)
SQLiteDatabase db = mOpenHelper.getWritableDatabase();
Cursor result = qb.query(db, projection, args.where, args.args, null, null, sortOrder);
result.setNotificationUri(getContext().getContentResolver(), uri);
return result;
}
@Override
public Uri insert(Uri uri, ContentValues initialValues) {
SqlArguments args = new SqlArguments(uri);
SQLiteDatabase db = mOpenHelper.getWritableDatabase();
final long rowId = db.insert(args.table, null, initialValues);
if (rowId <= 0) return null;
uri = ContentUris.withAppendedId(uri, rowId);
sendNotify(uri);
return uri;
}
@Override
public int bulkInsert(Uri uri, ContentValues[] values) {
SqlArguments args = new SqlArguments(uri);
SQLiteDatabase db = mOpenHelper.getWritableDatabase();
db.beginTransaction();
try {
int numValues = values.length;
for (int i = 0; i < numValues; i++) {
if (db.insert(args.table, null, values[i]) < 0) return 0;
}
db.setTransactionSuccessful();
} finally {
db.endTransaction();
}
sendNotify(uri);
return values.length;
}
@Override
public int delete(Uri uri, String selection, String[] selectionArgs) {
SqlArguments args = new SqlArguments(uri, selection, selectionArgs);
SQLiteDatabase db = mOpenHelper.getWritableDatabase();
int count = db.delete(args.table, args.where, args.args);
if (count > 0) sendNotify(uri);
return count;
}
@Override
public int update(Uri uri, ContentValues values, String selection, String[] selectionArgs) {
SqlArguments args = new SqlArguments(uri, selection, selectionArgs);
SQLiteDatabase db = mOpenHelper.getWritableDatabase();
int count = db.update(args.table, values, args.where, args.args);
if (count > 0) sendNotify(uri);
return count;
}
private void sendNotify(Uri uri) {
String notify = uri.getQueryParameter(PARAMETER_NOTIFY);
if (notify == null || "true".equals(notify)) {
getContext().getContentResolver().notifyChange(uri, null);
}
}
static class SqlArguments {
public final String table;
public final String where;
public final String[] args;
SqlArguments(Uri url, String where, String[] args) {
if (url.getPathSegments().size() == 1) {
this.table = url.getPathSegments().get(0);
this.where = where;
this.args = args;
} else if (url.getPathSegments().size() != 2) {
throw new IllegalArgumentException("Invalid URI: " + url);
} else if (!TextUtils.isEmpty(where)) {
throw new UnsupportedOperationException("WHERE clause not supported: " + url);
} else {
this.table = url.getPathSegments().get(0); ///content://com.android.launcherdemo.settings/favorites?notify=true;
this.where = "_id=" + ContentUris.parseId(url);
this.args = null;
}
}
SqlArguments(Uri url) {
if (url.getPathSegments().size() == 1) {
table = url.getPathSegments().get(0);
where = null;
args = null;
} else {
throw new IllegalArgumentException("Invalid URI: " + url);
}
}
}
}
配置文件中定义：
<provider android:name="com.android.test.broadcast.MyContentProvider" android:authorities="hello"></provider>